If you truly love your Apple computer, give it Kingston memory. Our legendary reliability & 100-percent testing make Kingston an ideal choice for Apple. Plus, every module comes with a lifetime manufacturer warranty. Kingston is the worlds largest independent memory manufacturer. In todays performance-driven environment, memory upgrades provide an easy, economical alternative to increase system performance. Every memory product Kingston offers is designed to help you get maximum performance at the best price to you. One of the best ways to improve your Macs performance Some applications such as photo & video editing, that run best on the Mac, can use a lot of memory. Thats why outfitting your Mac with Kingston Mac Memory is one of the best things you can do to maximize your systems performance & agility. Upgrading memory can also be a cost-effective way to get more life out of your older system: before you trade up to a new one, just upgrade the memory. DDR3 is the third generation of Double Data Rate (DDR) SDRAM memory. Similar to DDR2, it is a continuing evolution of DDR memory technology that delivers higher speeds (up to 1600 MHz), lower power consumption & heat dissipation. It is an ideal memory solution for bandwidth hungry systems equipped with dual & quad core processors & the lower power consumption is a perfect match for both server & mobile platforms. Dual In-line Memory Modules, or DIMMs, closely resemble SIMMs. Like SIMMs, most DIMMs install vertically into expansion sockets. The principal difference between the two is that on a SIMM, pins on opposite sides of the board are tied together to form one electrical contact; on a DIMM, opposing pins remain electrically isolated to form two separate contacts. Kingston Technology Known Compatibility list for KTA-MB1066/4G Apple Mac Book Pro (DDR3) 13-inch (Aluminum Mid-2009) Apple Mac Book Pro (DDR3) 13-inch (Mid-2010) Apple Mac Book Pro (DDR3) 15-inch (Aluminum Mid-2009) Apple Mac Book Pro (DDR3) 15-inch (Core i 5/i 7 Mid-2010) Apple Mac Book Pro (DDR3) 17-inch (Aluminum Early 2009) Apple Mac Book Pro (DDR3) 17-inch (Aluminum Mid-2009) Apple Mac Book Pro (DDR3) 17-inch (Core i 5/i 7 Mid-2010) Apple i Mac Intel Core 2 Duo 20-inch/24-inch (Early 2009) Apple i Mac Intel Core 2 Duo 21.5-inch (Late 2009) Apple i Mac Intel Core 2 Duo/i 5/i 7 27-inch (Late 2009)